Independent dimensions for QML-Items - qt

Question

I am using QQmlApplicationEngine and therefore have one root element and Item-s. Because I have one root file, to which all the methods connected from C++ (but still accessible in whole .qml directory) I can't make the other Item-s be independet from the dimension settings of the root. So if I make minimumwidth of the value 300, so the other Item-s going to have the same minimumWidth too.
The quesstion is, whether it's possible to make them independent from main.qml and be able set others dimensions.
Here is some code to make you idea what I am talking about:
main.cpp:
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
const QUrl url(QStringLiteral("qrc:/main.qml"));
QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
&app, [url](QObject *obj, const QUrl &objUrl) {
if (!obj && url == objUrl)
QCoreApplication::exit(-1);
}, Qt::QueuedConnection);
engine.rootContext()->setContextProperty("mqttClient",mqttClient);
engine.rootContext()->setContextProperty("math",math);
engine.load(url);
main.qml:
Window {
id:root
width: 400
height: 300
minimumWidth: 960
minimumHeight: 420
visible: true
title: qsTr("Dampfmaschine Client")
StackView {
id: stackView
initialItem: "LoginPage.qml"
anchors.fill: parent
}
Component{
id: login
LoginPage{}
}
Component{
id: measure_page2
MeasurePage2{}
}
function load_page(page){
switch(page){
case 'MeasurePage':
stackView.push(measure_page2);
break;
}
}
}

Answer 1

You can use the Binding type in QML to set a binding which can be optional. I propose to add some property in your pages, for example:
LoginPage {
property int windowWidth : 200
property int windowHeight : 300
}
Then in main, you put the Binding
Window {
id:root
width: 400
height: 300
minimumWidth: 960
minimumHeight: 420
visible: true
title: qsTr("Dampfmaschine Client")
Binding {
target: root
property: "width"
value: stackView.currentItem.windowWidth
}
Binding {
target: root
property: "height"
value: stackView.currentItem.windowHeight
}
StackView {
id: stackView
initialItem: "LoginPage.qml"
anchors.fill: parent
}
Component{
id: login
LoginPage{}
}
Component{
id: measure_page2
MeasurePage2{}
}
function load_page(page){
switch(page){
case 'MeasurePage':
stackView.push(measure_page2);
break;
}
}
}
This way, the window will always be bound to the current item of the stackView and you don't have to look after it.
Optionally you can also use implicitWidth and implicitHeight from the pages, leading to even less maintenance (but possibly some headaches with weird pages)